It takes 60 minutes for 7 people to paint 5 walls. how many minutes does it take for 10 people to paint 10 walls?

for this case we have by definition, if two lines are perpendicular, then the product of their slopes is -1.

then, given the following line:

so,

we are looking for m_ {2}:

then, the line is given by:

we find "b" replacing the given point:

finally, the equation is:

option c